The Influence of Injected Fluids on Microscopic Pore Structures in the Intersalt Dolomitic Shale Oil Reservoirs
Given their low porosity and permeability, intersalt dolomitic shale oil reservoirs need to be developed via large-scale hydraulic fracturing to achieve economic effects. However, various lithologies and salt materials make these reservoirs vulnerable to salt mineral dissolution and recrystallizatio...
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| Format: | Article |
| Language: | English |
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Wiley
2019-01-01
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| Series: | Geofluids |
| Online Access: | http://dx.doi.org/10.1155/2019/4923173 |
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| author | Tong Zhou Wei Yan Jianzheng Su Xianglu Tang Hao Tian Wenbo Li Kongyang Wang Ting Sun Ruyue Wang Rusheng Zhang Jun Niu |
| author_facet | Tong Zhou Wei Yan Jianzheng Su Xianglu Tang Hao Tian Wenbo Li Kongyang Wang Ting Sun Ruyue Wang Rusheng Zhang Jun Niu |
| author_sort | Tong Zhou |
| collection | DOAJ |
| description | Given their low porosity and permeability, intersalt dolomitic shale oil reservoirs need to be developed via large-scale hydraulic fracturing to achieve economic effects. However, various lithologies and salt materials make these reservoirs vulnerable to salt mineral dissolution and recrystallization and salt plugging during development. This study investigated the variation rules of pore structures, porosity, and permeability of intersalt dolomitic shale oil reservoirs under the influence of hydraulic fracturing fluid. Correspondingly, a series of experiments (i.e., high-temperature and high-pressure soaking experiments, focused ion beam scanning helium ion microscope analyses, and porosity and pulse permeability tests) is performed on the Qian 34-10 rhythmic intersalt dolomitic shales. Results show that distilled water dissolves the salt crystals inside the matrix pores to improve the reservoir permeability. However, the distilled water-rock interaction will cause the massive migration of salt minerals. By contrast, the supercritical CO2 can disperse salt particles, dredge the channels, and enlarge pores by expansion, but it has an overall weak capability of changing the pore structure and matrix permeability. To simulate the supercritical CO2 composite fracturing, the mixed solution of supercritical CO2 and distilled water favors the salt dissolution effect in the water-based fracturing fluid and recovery enhancement by CO2. This solution can remarkably improve the reservoir porosity and permeability and avoid massive salt mineral migration and salt crystallization damage. This study is theoretically and practically important to the effective and enhanced development of intersalt dolomitic shale oil reservoirs. |
| format | Article |
| id | doaj-art-7f5883d4516d487283ce10e57cc1858f |
| institution | Kabale University |
| issn | 1468-8115 1468-8123 |
| language | English |
| publishDate | 2019-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geofluids |
| spelling | doaj-art-7f5883d4516d487283ce10e57cc1858f2025-02-03T01:06:40ZengWileyGeofluids1468-81151468-81232019-01-01201910.1155/2019/49231734923173The Influence of Injected Fluids on Microscopic Pore Structures in the Intersalt Dolomitic Shale Oil ReservoirsTong Zhou0Wei Yan1Jianzheng Su2Xianglu Tang3Hao Tian4Wenbo Li5Kongyang Wang6Ting Sun7Ruyue Wang8Rusheng Zhang9Jun Niu10Research Institute of Petroleum Exploration and Development of SINOPEC, Beijing 100083, ChinaChina University of Petroleum-Beijing, Beijing 102249, ChinaResearch Institute of Petroleum Exploration and Development of SINOPEC, Beijing 100083, ChinaChina University of Petroleum-Beijing, Beijing 102249, ChinaChina University of Petroleum-Beijing, Beijing 102249, ChinaChina University of Petroleum-Beijing, Beijing 102249, ChinaChina University of Petroleum-Beijing, Beijing 102249, ChinaChina University of Petroleum-Beijing, Beijing 102249, ChinaResearch Institute of Petroleum Exploration and Development of SINOPEC, Beijing 100083, ChinaResearch Institute of Petroleum Exploration and Development of SINOPEC, Beijing 100083, ChinaResearch Institute of Petroleum Exploration and Development of SINOPEC, Beijing 100083, ChinaGiven their low porosity and permeability, intersalt dolomitic shale oil reservoirs need to be developed via large-scale hydraulic fracturing to achieve economic effects. However, various lithologies and salt materials make these reservoirs vulnerable to salt mineral dissolution and recrystallization and salt plugging during development. This study investigated the variation rules of pore structures, porosity, and permeability of intersalt dolomitic shale oil reservoirs under the influence of hydraulic fracturing fluid. Correspondingly, a series of experiments (i.e., high-temperature and high-pressure soaking experiments, focused ion beam scanning helium ion microscope analyses, and porosity and pulse permeability tests) is performed on the Qian 34-10 rhythmic intersalt dolomitic shales. Results show that distilled water dissolves the salt crystals inside the matrix pores to improve the reservoir permeability. However, the distilled water-rock interaction will cause the massive migration of salt minerals. By contrast, the supercritical CO2 can disperse salt particles, dredge the channels, and enlarge pores by expansion, but it has an overall weak capability of changing the pore structure and matrix permeability. To simulate the supercritical CO2 composite fracturing, the mixed solution of supercritical CO2 and distilled water favors the salt dissolution effect in the water-based fracturing fluid and recovery enhancement by CO2. This solution can remarkably improve the reservoir porosity and permeability and avoid massive salt mineral migration and salt crystallization damage. This study is theoretically and practically important to the effective and enhanced development of intersalt dolomitic shale oil reservoirs.http://dx.doi.org/10.1155/2019/4923173 |
| spellingShingle | Tong Zhou Wei Yan Jianzheng Su Xianglu Tang Hao Tian Wenbo Li Kongyang Wang Ting Sun Ruyue Wang Rusheng Zhang Jun Niu The Influence of Injected Fluids on Microscopic Pore Structures in the Intersalt Dolomitic Shale Oil Reservoirs Geofluids |
| title | The Influence of Injected Fluids on Microscopic Pore Structures in the Intersalt Dolomitic Shale Oil Reservoirs |
| title_full | The Influence of Injected Fluids on Microscopic Pore Structures in the Intersalt Dolomitic Shale Oil Reservoirs |
| title_fullStr | The Influence of Injected Fluids on Microscopic Pore Structures in the Intersalt Dolomitic Shale Oil Reservoirs |
| title_full_unstemmed | The Influence of Injected Fluids on Microscopic Pore Structures in the Intersalt Dolomitic Shale Oil Reservoirs |
| title_short | The Influence of Injected Fluids on Microscopic Pore Structures in the Intersalt Dolomitic Shale Oil Reservoirs |
| title_sort | influence of injected fluids on microscopic pore structures in the intersalt dolomitic shale oil reservoirs |
| url | http://dx.doi.org/10.1155/2019/4923173 |
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